libraries/Advisor.class.php

   1 <?php
   2 /* vim: set expandtab sw=4 ts=4 sts=4: */
   3 /**
   4  * A simple rules engine, that parses and executes the rules in advisory_rules.txt. Adjusted to phpMyAdmin
   5  *
   6  *
   7  * @package phpMyAdmin
   8  */
   9
  10 class Advisor
  11 {
  12     var $variables;
  13     var $parseResult;
  14     var $runResult;
  15
  16     function run() {
  17         // HowTo: A simple Advisory system in 3 easy steps.
  18
  19         // Step 1: Get some variables to evaluate on
  20         $this->variables = array_merge(
  21             PMA_DBI_fetch_result('SHOW GLOBAL STATUS', 0, 1),
  22             PMA_DBI_fetch_result('SHOW GLOBAL VARIABLES', 0, 1)
  23         );
  24         if (PMA_DRIZZLE) {
  25             $this->variables = array_merge($this->variables,
  26                 PMA_DBI_fetch_result(
  27                     "SELECT concat('Com_', variable_name), variable_value
  28                     FROM data_dictionary.GLOBAL_STATEMENTS", 0, 1));
  29         }
  30         // Add total memory to variables as well
  31         require_once 'libraries/sysinfo.lib.php';
  32         $sysinfo = getSysInfo();
  33         $memory  = $sysinfo->memory();
  34         $this->variables['system_memory'] = $memory['MemTotal'];
  35
  36         // Step 2: Read and parse the list of rules
  37         $this->parseResult = $this->parseRulesFile();
  38         // Step 3: Feed the variables to the rules and let them fire. Sets $runResult
  39         $this->runRules();
  40
  41         return array('parse' => array('errors' => $this->parseResult['errors']), 'run' => $this->runResult);
  42     }
  43
  44     function runRules() {
  45         $this->runResult = array(
  46             'fired' => array(),
  47             'notfired' => array(),
  48             'unchecked'=> array(),
  49             'errors' => array()
  50         );
  51
  52         foreach ($this->parseResult['rules'] as $rule) {
  53             $this->variables['value'] = 0;
  54             $precond = true;
  55
  56             if (isset($rule['precondition'])) {
  57                 try {
  58                      $precond = $this->ruleExprEvaluate($rule['precondition']);
  59                 } catch (Exception $e) {
  60                     $this->runResult['errors'][] = 'Failed evaluating precondition for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  61                     continue;
  62                 }
  63             }
  64
  65             if (! $precond) {
  66                 $this->addRule('unchecked', $rule);
  67             } else {
  68                 try {
  69                     $value = $this->ruleExprEvaluate($rule['formula']);
  70                 } catch(Exception $e) {
  71                     $this->runResult['errors'][] = 'Failed calculating value for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  72                     continue;
  73                 }
  74
  75                 $this->variables['value'] = $value;
  76
  77                 try {
  78                     if ($this->ruleExprEvaluate($rule['test'])) {
  79                         $this->addRule('fired', $rule);
  80                     } else {
  81                         $this->addRule('notfired', $rule);
  82                     }
  83                 }  catch(Exception $e) {
  84                     $this->runResult['errors'][] = 'Failed running test for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  85                 }
  86             }
  87         }
  88
  89         return true;
  90     }
  91
  92     /**
  93      * Escapes percent string to be used in format string.
  94      *
  95      * @param string $str
  96      * @return string
  97      */
  98     function escapePercent($str)
  99     {
 100         return preg_replace('/%( |,|\.|$)/','%%\1', $str);
 101     }
 102
 103     /**
 104      * Wrapper function for translating.
 105      *
 106      * @param string $str
 107      * @param mixed  $param
 108      * @return string
 109      */
 110     function translate($str, $param = null)
 111     {
 112         if (is_null($param)) {
 113             return sprintf(_gettext(Advisor::escapePercent($str)));
 114         } else {
 115             $printf = 'sprintf("' . _gettext(Advisor::escapePercent($str)) . '",';
 116             return $this->ruleExprEvaluate(
 117                 $printf . $param . ')',
 118                 strlen($printf)
 119             );
 120         }
 121     }
 122
 123     /**
 124      * Splits justification to text and formula.
 125      *
 126      * @param string $rule
 127      * @return array
 128      */
 129     function splitJustification($rule)
 130     {
 131         $jst = preg_split('/\s*\|\s*/', $rule['justification'], 2);
 132         if (count($jst) > 1) {
 133             return array($jst[0], $jst[1]);
 134        }
 135         return array($rule['justification']);
 136     }
 137
 138     // Adds a rule to the result list
 139     function addRule($type, $rule)
 140     {
 141         switch($type) {
 142             case 'notfired':
 143             case 'fired':
 144                 $jst = Advisor::splitJustification($rule);
 145                 if (count($jst) > 1) {
 146                     try {
 147                         /* Translate */
 148                         $str = $this->translate($jst[0], $jst[1]);
 149                     } catch (Exception $e) {
 150                         $this->runResult['errors'][] = sprintf(
 151                             __('Failed formatting string for rule \'%s\'. PHP threw following error: %s'),
 152                             $rule['name'],
 153                             $e->getMessage()
 154                         );
 155                         return;
 156                     }
 157
 158                     $rule['justification'] = $str;
 159                 } else {
 160                     $rule['justification'] = $this->translate($rule['justification']);
 161                 }
 162                 $rule['name'] = $this->translate($rule['name']);
 163                 $rule['issue'] = $this->translate($rule['issue']);
 164
 165                 // Replaces {server_variable} with 'server_variable' linking to server_variables.php
 166                 $rule['recommendation'] = preg_replace(
 167                     '/\{([a-z_0-9]+)\}/Ui',
 168                     '<a href="server_variables.php?' . PMA_generate_common_url() . '#filter=\1">\1</a>',
 169                     $this->translate($rule['recommendation']));
 170
 171                 // Replaces external Links with PMA_linkURL() generated links
 172                 $rule['recommendation'] = preg_replace(
 173                     '#href=("|\')(https?://[^\1]+)\1#ie',
 174                     '\'href="\' . PMA_linkURL("\2") . \'"\'',
 175                     $rule['recommendation']
 176                 );
 177                 break;
 178         }
 179
 180         $this->runResult[$type][] = $rule;
 181     }
 182
 183     private function ruleExprEvaluate_var1($matches)
 184     {
 185         // '/fired\s*\(\s*(\'|")(.*)\1\s*\)/Uie'
 186         return '1'; //isset($this->runResult[\'fired\']
 187     }
 188
 189     private function ruleExprEvaluate_var2($matches)
 190     {
 191         // '/\b(\w+)\b/e'
 192         return isset($this->variables[$matches[1]])
 193             ? (is_numeric($this->variables[$matches[1]])
 194                 ? $this->variables[$matches[1]]
 195                 : '"'.$this->variables[$matches[1]].'"')
 196             : $matches[1];
 197     }
 198
 199     // Runs a code expression, replacing variable names with their respective values
 200     // ignoreUntil: if > 0, it doesn't replace any variables until that string position, but still evaluates the whole expr
 201     function ruleExprEvaluate($expr, $ignoreUntil = 0)
 202     {
 203         if ($ignoreUntil > 0) {
 204             $exprIgnore = substr($expr,0,$ignoreUntil);
 205             $expr = substr($expr,$ignoreUntil);
 206         }
 207         $expr = preg_replace_callback('/fired\s*\(\s*(\'|")(.*)\1\s*\)/Ui', array($this, 'ruleExprEvaluate_var1'), $expr);
 208         $expr = preg_replace_callback('/\b(\w+)\b/', array($this, 'ruleExprEvaluate_var2'), $expr);
 209         if ($ignoreUntil > 0) {
 210             $expr = $exprIgnore . $expr;
 211         }
 212         $value = 0;
 213         $err = 0;
 214
 215         ob_start();
 216         eval('$value = '.$expr.';');
 217         $err = ob_get_contents();
 218         ob_end_clean();
 219         if ($err) {
 220             throw new Exception(strip_tags($err) . '<br />Executed code: $value = '.$expr.';');
 221         }
 222         return $value;
 223     }
 224
 225     // Reads the rule file into an array, throwing errors messages on syntax errors
 226     function parseRulesFile()
 227     {
 228         $file = file('libraries/advisory_rules.txt');
 229         $errors = array();
 230         $rules = array();
 231         $ruleSyntax = array('name','formula','test','issue','recommendation','justification');
 232         $numRules = count($ruleSyntax);
 233         $numLines = count($file);
 234         $j = -1;
 235         $ruleLine = -1;
 236
 237         for ($i = 0; $i<$numLines; $i++) {
 238             $line = $file[$i];
 239             if ($line[0] == '#' || $line[0] == "\n") {
 240                 continue;
 241             }
 242
 243             // Reading new rule
 244             if (substr($line, 0, 4) == 'rule') {
 245                 if ($ruleLine > 0) {
 246                     $errors[] = 'Invalid rule declaration on line '.($i+1). ', expected line '.$ruleSyntax[$ruleLine++].' of previous rule' ;
 247                     continue;
 248                 }
 249                 if (preg_match("/rule\s'(.*)'( \[(.*)\])?$/",$line,$match)) {
 250                     $ruleLine = 1;
 251                     $j++;
 252                     $rules[$j] = array( 'name' => $match[1]);
 253                     if(isset($match[3])) $rules[$j]['precondition'] = $match[3];
 254                 } else {
 255                     $errors[] = 'Invalid rule declaration on line '.($i+1);
 256                 }
 257                 continue;
 258             } else {
 259                 if ($ruleLine == -1) {
 260                     $errors[] = 'Unexpected characters on line '.($i+1);
 261                 }
 262             }
 263
 264             // Reading rule lines
 265             if ($ruleLine > 0) {
 266                 if (!isset($line[0])) {
 267                     continue; // Empty lines are ok
 268                 }
 269                 // Non tabbed lines are not
 270                 if ($line[0] != "\t") {
 271                     $errors[] = 'Unexpected character on line '.($i+1).'
 272                         . Expected tab, but found \''.$line[0].'\'';
 273                     continue;
 274                 }
 275                 $rules[$j][$ruleSyntax[$ruleLine++]] = chop(substr($line,1));
 276             }
 277
 278             // Rule complete
 279             if ($ruleLine == $numRules) {
 280                 $ruleLine = -1;
 281             }
 282         }
 283
 284         return array('rules' => $rules, 'errors' => $errors);
 285     }
 286 }
 287
 288 function PMA_bytime($num, $precision)
 289 {
 290     $per = '';
 291     if ($num >= 1) { # per second
 292         $per = "per second";
 293     } elseif ($num*60 >= 1) { # per minute
 294         $num = $num*60;
 295         $per = "per minute";
 296     } elseif ($num*60*60 >=1 ) { # per hour
 297         $num = $num*60*60;
 298         $per = "per hour";
 299     } else {
 300         $num = $num*60*60*24;
 301         $per = "per day";
 302     }
 303
 304     $num = round($num, $precision);
 305
 306     if ($num == 0) {
 307         $num = '<'.pow(10,-$precision);
 308     }
 309
 310     return "$num $per";
 311 }
 312
 313 ?>